Construction toys are popular with young children, providing various structural elements capable of being assembled by the user in various combinations, either according to provided plans or on a free form basis of the user's own concepts. One of the well known and popular construction toy systems, marketed by K'NEX Industries, Inc. is the “K'NEX®” product, which is described and claimed in a number of U.S. patents, among them U.S. Pat. Nos. 5,061,219, 5,137,486, 5,199,919, 5,350,331, the disclosures of which are incorporated herein by reference.
The construction toy system disclosed in the foregoing U.S. patents comprises an arrangement of rods and connectors, in which the rods can be assembled with the connector sockets with a lateral, snap-in motion. Once assembled with a connector, a rod is held against axial separation by means of an annular groove in the rod which cooperates with opposed rib-like projections in the connector socket. The end of the rod also has a cylindrical portion which cooperates with axially oriented grooves formed in opposite sidewalls of the connector socket, at the open end portion of the socket. Following the snap-in assembly of the rod, the cylindrical end portion of the rod is held snugly within the axial grooves of the socket to maintain the rod firmly up in the grip of the socket. The described system enables strong and complex structures to be assembled and accommodates an extraordinarily wide variety of structural arrangements with both static and dynamic features.